Ferronickel-chromium alloy



Patented Apr. 8, 1924.

mural) sures PIERRE GIRIN. OF PARIS, FRANCE, ASSIGNOR TO SOCIETE ONYMEDE CQMMENTRY,

PATENT oFrlcE.

FOURCHAMBAUL T d; DEGAZEVILLE, OF PARIS, FRANCE.

rnanourcxancmiomim ALLOY.

No Drawing.

To all whom it may concern:

. Be it known that I, PIERRE Gram, a citizen of the Republic of France,residing in Paris, France, have invented certain new e and usefulImprovements in Ferronickel- Chromium Alloys, of which the following isa specification.

One of the first applications of steels chanical resistance associatedwith t e com-T is plete absence of brittleness, their resistance to wearand to rust, and, finally, by the possibility of avoiding, by ajudicious choice of the coefiicient of expansion, which varies between 0and 18 x per degree at according to the content in nickel, displacementand leakage, inevitable when we associate in athermal machine materialshaving diilerent coefiicients of expansion. But experience has shown aconsiderable drawback in the use of ferro-nickels in contactwith steamor hot and moist gases, a drawback which has entirely proscribed its usefor members exposed to the atmospheresv above mentioned; light pittingsdue to rust 80 appear and ultimately produce fissures. These fissuresextend from point to point, are opened by the play due to vibration, andrapidly become larger, finally compromising the solidity of the memberattacked.

After a minute study of the conditions and the processes of the attack,it has. been 0 possible to discover the remedy.

The present invention concerns an alloy of iron, nickel and chromium,including, 1 perhaps, tungsten, molybdenum, cobalt,

vanadium an titanium, presenting mechanical qualities superior to thoseof the ferro-nickels and absolutely refractory to any local attack, orto corrosion in saturated or superheated steam or moist or hot gases.

Alloys according to the present invention contain besides iron:

menu... 25 to 40 Chromium 10 to 15 -Manganese 0.5 to 1 Carbon 0.3 to 180 per cent.

Application filed December 9, 1918. Serial No. 205,986.

and may contain in addition any one or more of the following:

Cobalt 0 to 10 per cent. Tungsten '2 to 5 f Molybdenum 1 to 3 Vanadium0.2 to 1 Titanium Such additions of cobalt, tungsten, molybden-um,vanadium and (or) titanium in the proportions above stated may be madein order to improve the mechanical properties of the alloy, but they arenot essential. Such additions are made at the expense of the proportionof iron remainin' We can modify the composition between wide limitswithout changing the essential quality of the steel which is aresistance to alteration under the conditions mentioned. An addition oftungsten, molybdenum, or cobalt, permits the mechanical resistance to beincreased from kgs. up ta 90 or 100 kgs. and improves the resistance.

to Wear without increasing brittleness. The working can be facilitatedand also the quality improved by an additionjof vanadium or titanium.

According to the content in nickel adopted the coefiicient of expansionwill vary from 8 to 17 x'lO'. It is consequently possible to obtain apredetermined expansibility, foraexample, that of steel, 11 x 10", I

or bronze 17 x 10.

Chromium in large quantities has not only the efiect of rendering themetal more resistant and inoxidizable, but completelyprevents thehysico-chemical phenomena to which are ue the pittings and local changespeculiar to ferro-nickels. 7

Having thus described the nature of the said invention and the bestmeans 'I know of carrying the same into practical effect, I

cent, chromium, 10 to 15 per cent,'manganese, 0.5 to 1 per cent, andcarbon, 0.3 to 1 per cent, such alloy being inoxidizable and unalterablein superheated steam and in moist and hot gases, havin' high mechani:

' i cal resistance. without britt ene'ss and great resistance to wear,and having any required Q i I I 1361x243 coefii'eient ofexpansionbetween 8 and 17 x from 1 to 5 per cent.of e-metal in the na- 10",notably those of steel, bronze or. glass. 'ture of tungsten.

2. The'alloyof claim 1; conta'inin also 4. The alloy of claim 1,containing also 10 from 1 to 5 per cent of a metal in t e 1111- from 1ta 5 per cent'of molybdenum. 5 ture of tungsten, and from 0.1 to 1 percent In .witness whereof, I have" hereunto of a metal in the nature ofvanadium. signed my name. I

3. The alloy of claim 1, containing also I PIERRE GIRIN.

